Television circuit



June 30,A 1953 G. w. FYLER ETAL TELEVISION CIRCUIT 3 Sheets-Sheet. 1

Filed July 10, 1951 INVENToRs. 5%

June 30, 1953` G. W..FYLER Erm. 2,644,104 TELEVISION CIRCUIT June 30, 1953 G. w. FYLER Erm. 2,644,104

TELEVISION CIRCUIT Filed July 10, 1951 3 Sheets-Sheet 3 picture.

Patented June 30, 1953 UNITED l STATES yPATENT I OFFICE TELEVISION CIRCUIT George W, Fyler and Lawrence J. Mattingly,

Lombard, 111., assignors to Motorola,1nc., Chicago, Ill., a corporation of Illinois Application July 1o, 1951, serial No. 235,945

15 claims. (c1. 315-27) This invention relates to cathode ray beam deflection circuits and more particularly to circuits for producing horizontal sweep and high voltage for the tube of a television receiver, which are adjustable to vary the horizontal size of the Horizontal sweep circuits using a damper tube and a series bootstrap circuit are used extensively is television receivers to supply horizontal sweep current and accelerating voltage to the invention will be more readily apparent from the following description when read in connection with the accompanying drawings in which:

Figure 1 is a block diagram of a television receiver including a circuit diagram of a deflection i circuit embodying the invention;

cathode ray tubes thereof, and the advantages of such circuits are well known. To obtain horizontal size control with circuits of this type, it has been the usual practice to employ a variable inductance connected across a portion of the This arrangement provides satis' It is accordingly one of the objects of the present invention to provide a cathode ray beam deflecting circuit in which horizontal size adjustment is obtained very simply and inexpensively and yet very effectively.

Another object is to provide a circuit in which horizontal size adjustment is effected by adjusting the coupling choke unit of the sweep circuit itself without requiring any separate 0r additional units. Y

A further object is to provide a coupling choke unit for use in a cathode ray beam deflection and acceleration circuit which is constructed so that either the horizontal sweep current or the acceleration voltage may be varied independently of the other.

' Figure 2 is a top plan view of a coupling choke unit embodying the invention;

Figure 3 is a section on the broken line 3-3 of Figure 2;

Figure 4 is a vsection on the line 4--4 of Figure 3;

Figure 5 is a diagram illustrating the effect of the adjustment; and

Figure 6 illustrates a second embodiment of the invention.

As shown in Figure l,`atelevision receiver to which the invention is applied maycomprise an antenna system I0 to pick up transmitted signals and-supply them toa radio frequency amplifier Il. The amplified signals are fed to a converter I2, an intermediate frequency amplifier I3, and

` a detector I4. From the detector the signals are According to one feature of the invention, a

horizontal sweep circuit is provided having a coupling choke with a core which is adjustable for varying the sweep current without substantially affecting the Yhigh accelerating voltage which is derived from the same unit. Alternatively, an adjustment of the core may be provided for controlling the high accelerating voltage independently of the sweep current.

fed to a video amplifier l5, the audio signals passing through' to a Soundsystem I6 terminating in a loud speaker I1.

From the video amplifier, the video signals may be applied to a control electrode I8 of the cathode ray 'tube I9 to vary the beam intensity. Video signals are also supplied to a synchronization signal separator 2| which separates the vertical and horizontal synchronization pulses and supplies them respectively to a vertical deilection system 22 and a horizontal system including sawtooth generator 23. The vertical defiection system 22 is connected to vertical deflection windings 24associated with the tube I9 to control vertical sweep of the beam therein in the usual manner. The horizontal sawtooth generator 23 is connected through an output circuit to horizontal deflection windings 25 to provide sawtooth currents to control horizontal sweep of the beam. The output circuit also includes meansv providing a voltage for the acceleration anode in tlc tube, which is applied through a connection The horizontal output or sweep circuit as shown in Figure l includes an amplier tube 2l having a control grid 28 connected through a condenserr 29 to the horizontal sawtooth generator 23- and biassed to ground by a resistor 3|. As shown, the tube 21, has a'cathode connected to ground, a screen grid 32 connected to a positive potential designated plus B1, and an anode 33 connected to achoke 30. The choke 30 serves as an autotransformer and includes windings 34,

and 36 connected in series and provided on a core formed of sections 43 and 44. The windings 34 and 35 together form the primary section, winding 35 forms the sweep secondary section, and windings 34, 35 and 36 connected in series form the high voltage secondary section.

Theanode 33 of.tube 21 is.connected tothe primary section (34 and 35)A of fthe choke windings, and through condenser 31 to plus B'z, which is higher than B1. The circuit also includes a damper efficiency diode 42 whose anode is.con nected to plus B2, and whose cathode is connected to the common point-*between thewinding sections'34 and 35.*. Theffdiode is bridged by a condenser 38. The winding section 35 is' connected to the horizontal deflection-.coils 25 through condenser 20. A condenser 25a is bridged across one of the coils 25 to prevent ringing currents fromfdistorting the sweep. The

winding sections 34 and 35 therefore: 'form an autotransformer for providing theoutput sweep current, and as the transformer.` primary yinrcludes both sections 34 'and 35 and thesecondary .mary includes only the sections 34Y and 35 and the secondary includes the. sections 34, 3'5'and 36, the ioutput .voltage isxstepped up thereby. A

filament winding 4I may be provided on lthe core 43, 4'4 to :furnish :heating current for the .L cathode 'of ithediode 39.

Consideringth'e `operation othercircuit as so. far described, :thezthorizontal sawtooth gen- --erator provides. .arr;:exciting.. sawtoothf voltage wave to the grid 28 offthe:tub'e21. '.Thisvoltage fwave is of sufficient amplitude sc thatzthe tube is biased by; grid :current :and plate-currentA flows only. during. the "latter: portion,: approximately two-thirds, of the sweepzcycla Thefplate cur- .frent .builds up to iai-maximum at .which time the .tube 21 isl suddenly: cutoff.,` rleaving considerable stored nmagnetic energy in the yoke windings 25.and the primaryvcoils 34, 35. 'Ihe amount of stored energydepends upon thev rela` y tively large 'plate' voltage applied to` tube 21 which is .not only the B pluszvoltage, but` also theadded bootstrap voltage developed on condenser 31.

During `therretrace; theinductivestored energy discharges intothe:circuitlcapacity comprising condenser. 38 plus `the l:various-.stray ."icapaciti'es Yassociated with the` autotransformer windings 34, 35 and 36p1'od11cing'a half cycle of. oscillation inithe form of ahigh voltage pulse.

The .oscillation isqterminated by the. damper diode 42 `vwhen .the .magnetic energy is aamaxiimum in the opposite directionrand the Voltage at thecathode of diode 42 Atends to gonegative with respect to plus B2 at the anode thereof. Thismeans that atnegativevoltage equal approximately to theypotentialappearing incon- .denser 31 is allowed to "developacross thewinding 35 andthe yoke.;This.potential'controls the rate of decay of the current in thetyoke based on .thet formula:

Er= Ldi/dt The totalchange in current during the damper tube .conduction is, of `course,dependent upon the original stored energy and follows the relation:

The circuit losses must, of course, be considered. The damper tube conducts at about 1 @thezsame rate of current-change asthe sweep .;...tube in so far as theyoke Acurrent is concerned,

so that a substantially linear sweep results. The damper tube only conducts for about one third of the trace portion of the cycle and the action is'similar to that of a class B amplifier in the ergystored inv 31 is, of course, added to that provided by the power supply for operating the tube 21 during its conduction period. The

.windings 34, 35, and the yoke inductancemust be properly apportionedor bestlinearity vand r. efficiency. .Values which have been found to be to the operation of the system but .has been .found to. provide improved results.V This con- ..denser operates to. lengthen. thefhigh. voltage .pulse so.that regulation ofthe .high. `voltage ,supply is thereby improved. Further, it reduces ringing in Vthewindings andthereby improves 1.. thelinearity. It has .beenfound. thatthis condenser serves to tune thewindings to some extent size.

The coupling .choke .unit as `more particularly illustrated in Figures-2, 3. and 4 comprises a `magnetic core on which the 'windings 34, 35. and Y 36 .are `mounted... The core is rectangular. in

section and is formed of .two VU-shaped portions 43A and 44..'which are fitted together with the .ends of the' legs in` abutting relationship. The windings 34. .and 35. are-wound one over .the Yother on the insulating form 40,. and are placed about one of the abutting legs on Oneside' of the core, substantially symmetrically .with respect to the junction therebetween. The high voltage winding 36 is wound on form 40a, which `.may be-identical with form 40,.and is placed on the other side symmetrically with respect to The in which the diode rectifier 39 may be mounted.

As shown, vthe `socket and the core portion 44: are rigidly mounted on .a plate 46 formed of insulating material by which the .unit may be mounted in the chassis.

. The uppercore portion 43 is .held against the Alowercore portion 44 by a leaf spring 41.which .extends through an opening in the plate 4S and hasa tongue 48 bent therefrom to engage the plate thereby to anchor the lower end of the spring. The spring is bent over at its upper end as indicated at 49. and. extends through an opening in a strip 5|, which may be of brass,V

which overlies the .upper core portion 43.. The

, thisl leg part thereof under all conditions.

spring 41 is arranged at the same end of the core as the high voltage winding 36 to .hold the ends of the core legr portions rmly together by means of a clamp 52 so that the strip can serve to move the core portion. For this purpose a rod 53 is mounted in the plate 4B for free rotation therein Vbut is held against axial sliding by a C washer 54. At its outer end the rod terminates in a shaft portion 55 by which it may be turned to effect the adjustment and at its upper end the rod has a threaded portion 56 which is threaded onto the end of the strip 5l.` Preferably a C- washer 51 is secured to the end of the rod to pre vent accidental removal of the strip 5I.

By turning the rod 53 the core portion 43 can be swung about its right leg as a pivot to open to the desired extent an air gap in its left leg which is substantially in register with the primary and secondary windings 34 andV 35. When the rod is turned to close this air gap, maximum coupling will be obtained between the primary and secondary windings so that the horizontal sweep current will reachlits maximum value and the picture will be of maximum size. As the rod is turned to open the air gap as shown in Figure 3, the reluctance of the magnetic path through the primary and secondary winding sections will be increased to decrease the effective inductance of the windings. This will reduce the horizontal sweep current to reduce the picture size. The air gap in the right leg of the core within the high voltage Windingr36 will, however, be substantially uneffected so that the high voltage produced will remain substantially constant The effect of the adjustment on the horizontal sweep current and on the accelerating voltage is indicated by the curves shown in Figure 5. In these curves the horizontal distance indicates turns of the control rod 53 from its closed toward its open position, which is a measure of the air f gap opening. The solid curve 58 is calibrated in terms of accelerating voltage kilo-volts as indicated by the scale at the lefthand side of the graph. The dotted curve 59 indicates horizontal picture size in inches as indicated by the scale at the righthand side of the graph.

It will be seen from these curves that if'the air gap is opened, the horizontal size of the -picture is reduced substantially according to a straight line function. At the same time there is a slight increase followed by a slight fall oif in accelerating voltage. This change, however, is not suificient to effect materially the accelerating voltage such as to require refocusing. Alarge range in horizontal size control is obtained without effecting horizontal linearity in the particular circuit shown.

The above curves were produced by a unit which is shown in substantially full scale in the drawing. The `core is made of material having a very high permeability (ferrite) and has a cross-section approximately T95 of an inch square. Each U-shaped portion has legs spaced apart on the inside by about l 1A; inches and extending from the bight portion approximately 1/2 an inch. To produce the required deflection and high voltage for a 1'7-inch picture tube, the sections 34 and 35 together include approximately 750 turns with the f section 35 having approximately 450 of the turns.

The high voltage winding 36 has approximately 1000 turns.

The choke described is used with a tube 21 of the 6BQ6 type, a tube 42 of the 12AX4 type and a tube 39 of the lBSGT type. The yoke 24 has an inductance of the order of 24 millihenrys. The coupling condenser 20 has a capacity of .1 microfarad, the condenser 38 a value of the order of 180 micromicrofarads, the condenser 31 a value of 10 microfarads, and the condenser 25a shunting one of the yoke windings a value of the order of 47 micromicrofarads. In this unit the junction of the core portions under the windings 34 and 35 has a fixed minimum gap of approximately 7 mils which prevents direct current saturization of the core. This gap is increased to as much as t/B of an inch to provide Vthe size control previously described.

It has been found that if the air gap at the right side of the core is varied while the air gap at the left side is kept constant, the picture size stays substantially constant whereas the high voltage changes rapidly and requires refocusing. For use in television, it is desirable to keep the high voltage as high as possible and to keep it uniform so that definition, contrast, and brightness remain fixed. In certain other applications it may -be desirable to vary the high voltage and a choke structure for accomplishing this is illustratedv in Figure 6. In Figure 6 the components may be generally similar to those previously described except that an adjusting rod is provided for changing the gap at the right side of the core, in addition to the adjusting rod for changing the ga-p at the left side. In such a unit by turning the control rod 50, the high voltage produced by the unit at the terminal 6l can be controlled substantially independently of the sweep output which is derived from the terminals 62. As previously described, by the use of the control rod 63, the sweep current at the output terminals y52 can be controlled substantially independently of the high voltage produced with the terminal 6 l It is obvious that by use of the two controls 50 and 63, both the sweep current and the high voltage can be adjusted.

It will be seen that by the present invention, an accurate and substantially linear size control is provided without requiring any expensive additional parts and simply by adjusting an air gap in the core of the coupling choke unit itself. This is accomplished without appreciably affecting the high voltage and without introducing any complications into the circuit.

l While certain embodiments of the invention Yhave been shown and described in detail, it will be understood that these are illustrative only, and are not to be taken as a definition of the scope of the invention,lreference being had for this purpose to the appended claims.

We claim:

1. A cathode ray beam deflecting circuit of the type which includes a sawtooth current generator for delivering cyclically varying current to electromagnetic deflection means associated with a cathode ray tube, and which also includes rectifier means for delivering accelerating voltage to an accelerating anode of said tube, said circuit including an autotransformer coupling choke unit having a magnetic core and first and second winding sections in spaced relation thereon, said first winding section being connected to the sawtooth current generator to be energized thereby and serving as a primary winding, means connecting the deflection means in parallel with at least a portion of said first winding section for providing sawtooth current waves therein, saidsecond Winding section being connected in series with said first winding section and being -coupled to the rectifier means, and adjusting means for varying the magnetic reluctance of said core adjacent one of said winding sections.

2. A transformer assembly for use in a circuit for providing beam deflecting current and beam accelerating voltagefor ay'cathode rayztube, Said assembly including incombination, a magnetic core vformed of lrst and second-.coreI .members each including an elongated ,baseportion and f' arm portions extendingfrom the ends of said base portion so that said '.members are of generally U-shape, a supporting platefor said aswith; said' :first nivindingav means .being .positioned on said iirst section .thereof .about-fthe abutting f 1 1 arms, said rstzwindingfmeans serving` asY a- ,pr-

marywinding and' having :a part thereof, serving as a seconadry Winding so that the current is stepped up therein to provide the beam defiecting Hcurrent, means connecting ,said secondwwinding sembly, first supporting-means for supporting said rst core member on said supporting plate with said arms thereof extending away fromsaid plate, second supporting'means forxsaid second vcore member for holding the same with rthe Y i armsfthereof substantially in' abutment withthe arms of said iirst core member to form `a, substantially closed kmagnetic circuit; said second ysupporting means includingea strip extending along the-base portion of said second core member, means for securing said second core member to said strip, means extending along the abutting arms of said core'members on one side of said core and operatively connected to said strip. and said supporting plate to hold said abutting arms on said one side of said core in close engagement with each other, Vadjustable means operatively connected to said'strip for separating the abutting arms of said core members on the side of said core opposite to'said one side, tubular insulating forms positioned about said abutting arms of said core members on the opposite sides of said core, and rst and second winding means on said insulating forms, said first winding means being positioned on said insulating form on said opposite` side of said magnetic core and serving as an autotransformer for beam deflecting: current, said second winding means being positioned on said insulating Iform on said one side of said core and being connected vin series Ywith said first Winding means and serving as a high voltage winding. f 3. A transformer unit for a cathode ray beam deflecting and accelerating system including in combination, a magnetic core formed of two generally U-shaped portions, said portions being positioned to form a substantially closed magnetic circuit having opposite sides which include means in series with vsaid iirst winding means so'that thevoltage is stepped up therein Vtofprovidethebeam accelerating voltage, and supporting means for saidcoreportionsfor holding. said arms. thereof in .substantially abutting relation, said supporting means including adjustable means for separating Vthe abutting arms offsaid `core portions on said -iirsti section of said core `toY provideV an adjustable Agap therebetween. .and

thereby varytheireluctance of. thejluxpath bearn'accelerating voltage for a cathode ray tube,

said assembly including incombination, a magnetic core formed of first and second generally U- shaped portions, said portions being positioned to form a substantially closed magnetic structure having rst and secondy opposite-sides which include the abuttingarms ofsaid U-shaped `core portions," first and ysecond winding Ymeans individually positioned'about said abutting. arms on said rst andsecond sides of said'magnetic structure respectively, .said Vrst `windirigameans serving as a primary winding. and havinga part thereof serving asa secondary windingso that the currentV is stepped up therein to provide, the beam deiiecting current,means*connecting said second winding means in series :with .said Irst winding means so that Athe voltage is stepped up therein .to'provide the beamaccelerating voltage, and supportingmeansfor said core portions for 1 holding said armsLthereof in substantiallyabutthe abutting arms of said U-shaped core portions, iirst and second magnetically coupled winding z means individually positioned on said opposite sides of said core about said abutting arms, said rst winding means serving as a primary winding and having arportion thereof serving as a secondarywinding for providing beam deiiecting current, said second winding means'being connected in serieswith said first means and serving as a high voltage winding, and means for supl Yporting saidv core portions with the arms thereof in substantially abutting relation including- `adjusting means for varying the gap between abutting arms of said core portions adjacent said rst winding means to thereby vary the deflect- Y ing current produced by said choke unit without substantially affecting the high voltage produced l cluding in combination,.a magnetic core formed of Vfirst and second portions positioned to form a substantially closed magnetic structure, said core having rst and second sections which include the abutting arms of said corev portions, first and second winding means positioned about said core,

ting relation, said supporting means including Vadjustable means. for separating. the abutting larms of said core portions on 'said iirsty side of 'said core' to 'provide anV adjustable gap therebetween and therebyvary the-reluctance of' the fluxfpathathrough said irst` winding means, said 1'supportingrmeans including means' for holding the .abutting arms of said core portion on said second side of said :core substantially in engagement with each other.

6. In a television system which has therein a cathode ray tube and a circuit for providing beam deiiecting current and beam accelerating voltage therefor, Va transformer assembly for connection into the deflecting and accelerating circuit, said transformer assembly including in combination, a magnetic core formed of iirst and'second portions positioned to Vform a substantially closed magnetic structure, `said magnetic core having rst and second sides which include the abutting arms ofsaid coreportions, first and second winding means positioned about said magnetic "core, withl said first winding'means'being positioned on said first side thereof about the abutting arms, said first winding means-serving as an autotransformer for providing the beam deiiecting current, means connecting. said second winding means in serieswith said first winding means so that said rst and second winding means together form an autotransformer in which thevoltage is stepped Aup to provide'thegbeam :accelerating voltage, .and

supporting means for said lcore portions for holding said arms thereof in substantially abutting relation, said supporting means including adjustable means for separating the abutting arms of said core portions on said first side of said core to provide an adjustable gap therebetween and thereby vary the reluctance of the flux path through said first winding means, said supporting means including means for holding the abut- .ting arms of said core portions on said second side of said core substantially in engagement with each other.

7. A transformer assembly for use in a circuit for providing beam deflecting current and beam accelerating voltage for a cathode ray tube, said assembly including in combination, a magnetic core formed of first and second generally U- shaped portions, said'core portions being positioned to form a substantially closed magnetic structure having Vfirst and second opposite sides Which include the abutting arms of said U -shaped core portions, first and second Winding means individually positioned on said first and second sides of` said magnetic core respectively about said abutting arms of said core portions, said first Winding means serving as an autotransformerfor providing the beam deflecting current, means connecting said second Winding means in series withrsaid first Winding means so that said first and second winding means together form an autotransformer in which the voltage is stepped up to provide the beam accelerating voltage, and supporting means for said core portions for holding said arms thereof in substantially abutting relation, said supporting means including adjustable means for separating the abutting arms of said core portions on said iirst side of said core to provide an adjustable gap therebetween and thereby vary the reluctance of the flux path through said first Winding means, said supporting means including means for holding the abutting arms of said core portion on said second side of said core substantially in engagement with each other.v

8. A cathode ray beam deflecting circuit of the type which includes a sawtooth current generator for delivering cyclically varying current to electromagnetic deflection means associated with a cathode ray tube, and which also includes rectifier means for delivering accelerating voltage to an `accelerating anode of said tube, said circuit including a coupling choke unit having a magnetic core and winding means: thereon forming an autotransfofrmer, said winding means including -a primary winding connected to the sawtooth current generator to be energized thereby, means connecting the deflection means in parallel with a portion of said primary Winding which portion forms a secondary section thereof, and a high voltage Winding connected in series with Said prim-ary Winding to the rectifier means, said core having an air gap adjacent said primary Winding, and means to vary the length of the air gap to thereby vary the magnetic reluctance of said core adjacent said primary Winding and said secondary section thereof Without substantially affecting the voltage produced by said high voltage Winding.

9. A cathode ray beam deflecting circuit of the type which includes a sawtooth current generator for delivering cyclically varying current to electromagnetic deflection means associated with a cathode ray tube, and which also includes rectifier means for delivering accelerating voltage to an accelerating anode of said tube, said circuit including a coupling choke unit having a magnetic core and a winding thereon, said Winding including a primary section connected to the sawtooth current generator to be energized thereby, a secondary section including a portion of said primary section, means connecting the deilection means in parallel With said secondary section, and a high voltage section connected through the rectifier means to the accelerating anode, and adjusting means for varying the magnetic reluctance of said core adjacent said primary and secondary sections for varying the amplitude of the current Wave applied to the deiiection means without substantially changing the amplitude of the high voltage applied to the accelerating anode.

10. In a cathode ray beam deecting and accelerating circuit, a coupling choke unit including a magnetic core formed of two U -shaped portions, said portions being .positioned to form a substantially closed magnetic circuit having opposite sides which include the abutting arms of said U-shaped core portions, iirst and second magnetically coupled winding sections individually positioned on said opposite sides of said core about said abutting arms, said first Winding section serving as a primary winding and having -a portion thereof serving as a secondary winding for providing deflecting current, said second winding section being connected in series with said first section and being spaced therefrom and serving as a high voltage Winding, and adjusting means for varying the gap 'between abutting arms of said core portions adjacent said Vsecond Winding section to thereby vary the high voltage produced by said choke unit without substantially affecting the deiiecting current produced thereby.

11. A cathode rayV beam deiiecting circuit of the type which includes a sawtooth current generator for delivering cyclically varying current to electromagnetic deflection means associated with a cathode ray tube, and which also includes rectifier means for delivering accelerating voltage to an accelerating anode of said tube, said circuit including a coupling choke unit having a magnetic core and first and second Winding sections in spaced relation thereon, said first winding section being connected to the sawtooth current generator to be energized thereby and serving as a primary Winding, means connecting the deflection means in parallel with a portion of said first Winding section for providing sawtooth current Waves therein, said second Winding section being connected in series with said first Winding section and being connected through the rectifier means to the accelerating anode, and adjusting means for varying the magnetic reluctance of said core adjacent said second winding section for varying the effective inductance off said second winding section to thereby vary the amplitude of the accelerating voltage produced thereby Without substantially changing the amplitude of the deiection current.

l2. A cathode ray beam deflecting circuit of the type which includes a sawtooth current generator for delivering cyclically varying current to', electromagnetic deiiection means associated with a cathode ray tube. and which alsoincludes iirst rectifier means for delivering accelerating voltage to lari accelerating anode of the tube, said circuit including an electric discharge valve having an output electrode, a coupling choke unit having a magnetic core and first and second Winding sections in spaced relation thereon, seciii 122Y ond rectiner means, condenser means', said nrstVVV means fori applying voltage-vpulsesathereto,fand Winding section connecting said output electrode second condenser tube bridged across saidrec of saidvalve tol said condenser means, means tii'lery means for reducing undesired oscillationsl'a connecting the-deection ymeans in parallel with in said winding section and for'lengtheningthe a portion of said first Winding section for prol- 5 voltage pulses appliedto the rectifier means. 1 viding-sawtooth current Waves therein, circuit- 15. A coupling' choke assemblyl for use in a. means connecting said second rectier "means circuit for providing' beam deecting currenti. and said portion of said -iirst Winding section in and beamaccelerating voltage for a cathode ray series with av source of potential to: said con-y tube, said coupling choke assembly' including inni denser means for charging the same, saidsecond l0 combination, a magnetic coreformed of rst winding section beingconnected in seriesrwith" and second core members Veach including. Van said rst Winding section and being coupled to elongated base portion and arms extendingk from the` nrst rectier means, and adjusting-means the ends thereof to provide membersv of sub for varying the magnetic reluctance of said Core tantially U-shape, a supporting platefor 'said-'1 adjacent said iirstiwinding section. Y l5 assembly, rst'supporting means for supporting 'r-"f 13. A cathode ray beam deleetingl circuit of said-first core member on said supporting plate the type which includes'a` sawtooth current genwith said armsthereofextending away fromsaidt i erator Vfor delivering cyclicallyvarying 'current'lplate, second supporting means for said4 second to electromagnetic denection-means associated core member for holding the same'with the arms. with a cathode ray tube, and which. also includes 20 thereof substantially in' abutment with the armsf: rectifier means for delivering accelerating voltof said iirst core member Ato forma snbsmnf-,i9,11i` age to an accelerating anode of the tube, said cir' ly closed magnetic circuit,` said second supporte-iffV cuit including an electric dischargeV valveV have ing means including a strip extending alongtlfie rlgfn 01113101115 eleCl'fOCe, -2 Coupling Choke unit base portion of saidseoond core..member,.clip having a magnetic core and 'rsta'nd second 25 means for securing said second core-member to ,fr winding means thereon, 'a rectifier tube, 'condensaid strip, spring means extending along-lthe-"` ser meanSfSaOl l'Sl Winding means Connecting abutting arms of saidv core members on one side said output electrode of saidlvalve to said con of said coreV and operatively connectedwto saidl denser -means, means connecting the Jdeection strip and said-Supportingplate to noldxsadabntl; means in parallel-.with a porti'on'of said first 30 ting arms on said one 'sideof said'l-corein 'close-12J windingv means vfor providing sav/tooth current engagementV with each other and.; 01jnsfajol 3.-Y;` waves therein, circuit means connecting said reomeans operatively connected :to said; Strip-,.-fforzp tiertube and saidportion. of said nrst Winding separating the abutting V@mns-0f Said Core mem means in series with-a source of potentialV to said bers on the side of said coreloppositeto sai condenser means for charging ythersame,` said 35 onerside, saidrst supportingrmeans including.:-A second Winding A'means being connected in series insulating means having .a tubular-1 portion. powv WithSd-YSt-Wndng-meels'ondbeilg Coupled sitioned about said abuttingarmslof saidcorev' to the reetel means for applying Voltage pulses members on said opposite. side of said' cores/*and tf1 thereto,y second Acondensenmeans bridged across rst and second windingzmeansabout saidsoreV-f.: said recti'er tubefor reducing...undesired oscil- 40 saidfirst winding.meanslbeingpositioned on sami` lations in said Winding mean'slandfor'lengthtubular portionrof saidinsulatingA means'abou elligfhe Voltage'llllSeSeDpled Ato the eetel saidrabutting arms on `saidvopposite side-fof sai' means', 'and .edl'uSting -mealSf for vVarying 'the 1 magnetic coreand serving as an autotransforxnerrl magnetic reluctance of saidcoreadjacent'Said for providing the beam deecting current,v Saidu.- nrst winding means. 45 second Winding meanslbeingi connected'series 14. A cathode ray beam' denectinglcircuit of with said first winding means .Tand serving! as aiu the type which includes a sawtoqth current genhigh voltage winding for providing the beam ac-z:.f erator for delivering cyclically varyingcurrent celerating- -voltage;; 1. Y to velectromagnetic deflection means `associated 

